We were the first group to identify multiple mutations in the desmin gene that caused myofibrillar myopathy. In addition, we have described a new variant of hereditary amyotrophic lateral sclerosis associated with a mutation in the SOD1 gene. Additionally, we have characterised a distinct form of prion encephalopathy caused by a novel mutation in the PRNP gene. We also presented evidence for digenic inheritance of malignant hyperthermia susceptibility in a large American family by detecting a novel mutation in the RYR1 gene and a strong linkage to the 7q11.23-21.1 region. We are CLIA-certified to perform genetic testing for spinocerebellar ataxias, desmin myopathy and prion diseases; 209 patients were tested during FY99. - Desmin myopathy; spastic paraplegia; spino-cerebellar ataxia; prion diseases.